If you’re on Ghost Pro (your domain is .ghost.io), you can always contact them at their support email: support@ghost.org
If you’re self-hosting, this community forum is a good place to ask!
I’m happy to try to help you figure this out, but I don’t understand your question. You said “Followed instructions to publish my first post, but a couple of days later its still not visible when I EXPLORE Ghost as a visitor.”
You mean when you go to your Ghost site’s url (without the /ghost), you don’t see the post? Or do you mean something else? (I think it’s the capitalized explore that’s confusing me, because there is a “Ghost Explore” that shows a selection of Ghost sites from around the web, but I wouldn’t expect a new site with one post to appear on it.)